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In this paper, a low voltage bandgap reference circuit has been proposed. The introduction of a modified beta multiplier bias circuit decreased the mismatch caused by the PMOS transistors opamp con...

Traditional BGR circuits require a 1.05V supply due to the V BE of the BJT. Deep submicron CMOS technologies are limiting the supply voltage to less than 940mV. Hence there is a strong motivation to design them at lower supply voltages. The supply voltage limitation in conventional BGR is described qualitatively in this paper. Further, a current mirror-assisted technique has been proposed to enable BGR operational at 0.82V supply. A prototype was developed in 65nm TSMC CMOS technology and post-layout simulation results were performed. A self-bias opamp has been exploited to minimize the systematic offset. Proposed BGR targeted at 450mV works from 0.82-1.05V supply without having any degradation in the performance while keeping the integrated noise of 15.2µV and accuracy of 23.4ppm/°C. Further, the circuit consumes 21µW of power and occupies 73*32µm2silicon area.

A compact high gain current mode instrumentation amplifier (IA) has been proposed for biomedical imaging applications. Conventional IAs rely on several matching resistors which occupies a lot of silicon area, the input and output common mode voltages are exactly same and the maximum applied signal amplitude is limited by internal node voltage swings. The present proposal eliminates the need for matching resistors by processing signals in the current mode. Hence input amplitudes are no longer limited by the voltage headroom and input and output common-mode voltages can be independent. An amplifier with a differential gain greater than 52 dB and a common mode rejection ratio greater than 120 dB has been implemented in 65 nm CMOS Technology and Post layout simulations were presented. The total circuit occupies 4500 μm2 silicon area and circuit consumes ~ 260 μA from 1.8 V power supply.

The performance requirement of an operational trans-conductance amplifier (OTA) for the high gain and low power neural recording frontend has been addressed in this paper. A novel split differential pair technique is proposed to improve the gain of the OTA without any additional bias current requirements. The design demonstrates a significant performance enhancement when compared to existing techniques, such as gain-boosting and recycling. A qualitative and quantitative treatment is presented to explore the impact of the split ratio on the performance parameters of gain, bandwidth, and linearity. A prototype implemented in TSMC 65 nm CMOS technology achieved 68 dB open loop-gain (13 dB higher than the conventional circuit) and a 17 kHz 3-dB bandwidth. A linearity of − 62 dB has been achieved with 7 mV pk–pk signal at the input. The circuit operates from a 1 V supply and draws 0.6 uA static current. The prototype occupies 3300 um2 silicon area.

Capturing a near-perfect, artefact free signal is an ideal of biomedicine. However, this depends on the removal of different types of artefact, all of which can be considered unwanted noise on the desired signal. Failure to remove artefacts could lead to a clinical misinterpretation of the results. All medical equipment such as electrocardiogram systems which use electrodes attached to patients suffer from artefacts, with effects ranging from minor blurring to significant distortion of the output signal(s). For this reason, it is important to identify how artefacts can influence the output signal. In this paper, we propose a new technique to detect and minimise movement artefacts using strain gauges embedded into the electrodes.

This paper proposes a system to detect and measure blink rate to determine fatigue levels. The method involved analysing specific frames to determine that a blink occurred, and then monitoring the time between successive blinks. The program was simulated in python using a Raspberry Pi Zero and a standard USB camera. For the blink rate detection block, a gate level schematic was implemented in Cadence software using 65 nm CMOS technology. The design was based around an asynchronous 6-bit based edge counter which was designed using D-flip-flops. The simulation calculated the average blink rate and compared this to the most recent blink rate. The outcome would determine if an alarm signal should be sent to the alarm. The system consumed 130 μA from a 1.2 V power supply.

Retinoblastoma is an ocular tumor that occurs in young children, in either heritable or sporadic manner. The relative rarity of retinoblastoma, and the need for expensive equipment, anesthesia, and pediatric ophthalmologic expertise, are barriers for effective treatment in developing countries. Also, with an average age-adjusted incidence of two to five cases per million children, patient number limits development of local expertise in countries with small populations. Lebanon is a small country with a population of approximately 4.5 million. In 2012, a comprehensive retinoblastoma program was formalized at the Children's Cancer Institute (CCI) at the American University of Beirut Medical Center, and resources were allocated for efficient interdisciplinary coordination to attract patients from neighboring countries such as Syria and Iraq, where such specialized therapy is also lacking. Through this program, care was coordinated across hospitals and borders such that patients would receive scheduled chemotherapy at their institution, and monthly retinal examinations and focal laser therapy at the CCI in Lebanon. Our results show the feasibility of successful collaboration across borders, with excellent patient and physician adherence to treatment plans. This was accompanied by an increase in patient referrals, which enables continued expertise development. However, the majority of patients presented with advanced intraocular disease, necessitating enucleation in 90% of eyes in unilateral cases, and more than 50% of eyes in bilateral cases. Future efforts need to focus on expanding the program that reaches to additional hospitals in both countries, and promoting early diagnosis, for further improvement of globe salvage rates.

Often Bandgap Reference performance limits the SNR of the bio-medical transceiver, hence sensitivity. In this paper, conventional beta multiplier has been explored to design a new low voltage pure CMOS bandgap architecture, which avoids op-amps and resistors, hence very less mismatch and area. Line sensitivity has been improved by adding an extra gain stage in the circuit. The circuit implementation of the proposed technique was done in 65 nm TSMC CMOS technology to generate 460 mV output voltage. The minimum operating voltage of the circuit is 650 mV. Post-layout simulation results are as follows, 31 ppm/\(^{\circ }\)C temperature coefficient against temperature variation of −40\(^{\circ }\) to 125 \(^{\circ }\)C, 0.5% regulation against supply variation of 0.65−1 V and 0.42% PVT variation. Circuit draws 2.3 A current from 650 mV from power-supply. The proposed band gap reference occupies 0.00144 mm\(^{2}\) silicon area.

In this paper two stage Miller compensated opamp has been discussed qualitatively and quantitatively. A modification to the conventional compensation network has been proposed, which will reduce the capacitor size hence circuit area. Transfer function for the newly proposed solution has been derived and explained the results. A prototype was developed in 65nm TSMC CMOS technology and simulation results have been presented. Amplifier achieved 60dB low frequency gain, 12MHz bandwidth and 55° phase margin while consuming 650uW power from 1.2V power supply. Circuit occupies 5348um 2silicon area.

Integrated low noise neural amplifiers become recently practical in CMOS technologies. In this paper, a low noise OTA technique has been proposed while keeping the power consumption constant. A capacitive feedback, ac coupled 46dB amplifier with high pass cutoff frequency close to the 90Hz has been achieved. The proposed amplifier has been implemented in 65nm CMOS technology; at room temperature circuit consumes 323uA current from 1.2V power supply. The circuit occupies 2627um2 silicon area.

In this paper, a PVT insensitive variable gain amplifier (VGA) has been proposed which is suitable for bio-medical neural recording. Proposed amplifier delivers an appreciably enhanced performance over that of existing technique. Constant Gm bias stability is described in the frequency domain. Noise problems with the existing technique are described qualitatively. A prototype circuit has been implemented in 65nm CMOS technology and simulated with Spectre. 2–25dB gain programmable range was achieved across PVT and 0.3dB standard deviation. 1.2uV integrated RMS noise was achieved. The circuit consumes 0.5mA from the 1.5V supply voltage and occupies 4500um2 silicon area.

In this paper a low power, high gain self bias opamp suitable for biomedical applications has been described. A novel trans conductance boosting technique is introduced without having any additional power consumption. A simple technique of biasing the opamp has been introduced for very low offset and without having any requirement for external reference circuit. A prototype of two stage amplifier design presented to verify the proposed technique and described its robustness across PVT variations by showing simulation results. The design is implemented in 45nm CMOS technology and simulated with Spectre. Simulation results show that the proposed opamp exhibits FOM of 625 and 2 times better than state of art. The circuit consumes 26uW from 1.5V supply and occupying 0.00282mm2 silicon area.

In this paper a low OpAmp compensation technique suitable for the bio-medical application has been proposed and intuitive explained the existing compensation techniques. The Present technique relies on the passive damping factor control rather power hungry damping. Implemented in 45nm CMOS technology and simulated with Spectre. Simulation results shows that 100dB dc gain, well compensated 25MHz bandwidth OpAmp while driving a 1pF capacitive load. Draws with 12uW power consumption from 1V supply and occupying 0.004875mm2 silicon areas.

In this paper a microwatt low voltage bandgap reference suitable for the bio-medical application. The Present technique relies on the principle of generating CTAT and PTAT without using any (Bipolar Junction Transistor) BJT and adding them with a proper scaling factor for minimal temperature sensitive reference voltage. Beta multiplier reference circuit has been explored to generate CTAT and PTAT. Implemented in 45nm CMOS technology and simulated with Spectre. Simulation results shows that the proposed reference circuit exhibits 1.2% variation at nominal 745mV output voltage. The circuit consumes 16uW from 0.8V supply and occupying 0.004875mm2 silicon area.

This paper explains the hidden positive feedback in a two-stage fully differential amplifier through external feedback resistors and possible DC latch-up during the amplifier start-up. The biasing current selection among the cascade branches has been explained intuitively, with reference to previous literature. To avoid the latch-up problem, irrespective of the transistor bias currents, a novel hysteresis-based start-up circuit is proposed. An 87[Formula: see text]dB, 250[Formula: see text]MHz unity gain bandwidth amplifier has been developed in 65[Formula: see text]nm CMOS Technology and post-layout simulations demonstrate no start-up failures out of 1000 Monte-Carlo (6-Sigma) simulations. The circuit draws 126[Formula: see text][Formula: see text]A from a 1.2[Formula: see text]V supply and occupies the 2184[Formula: see text][Formula: see text]m2 area.

This paper presents a fully integrated front-end, low noise amplifier (LNA), dedicated to the processing of various types of bio-medical signals, such as Electrocardiogram (ECG), Electroencephalography (EEG), Axon Action Potential (AAP). A novel noise reduction technique, for an operational transconductance amplifier (OTA), has been proposed. This adds a current steering branch parallel to the differential pair, with a view to reducing the noise contribution by the cascode current sources. Hence, this reduces the overall input-referred noise of the LNA, without adding any additional power. The proposed technique implemented in 65[Formula: see text]nm CMOS technology achieves 30 dB closed-loop voltage gain, 0.05[Formula: see text]Hz lower cut-off frequency and 100 MHz 3-dB bandwidth. It operates at 1.2[Formula: see text]V power supply and draws 1[Formula: see text][Formula: see text]A static current. The prototype described in this paper occupies 3300[Formula: see text][Formula: see text]m2 silicon area.

This paper describes a high-performance impedance measurement circuit for the application of skin impedance measurement in the early detection of skin cancer. A CMRR improvement technique has been adopted for OTAs to reduce the impact of high-frequency common mode interference. A modified three-OTA instrumentation amplifier (IA) has been proposed to help with the impedance measurement. Such systems offer a quick, noninvasive and painless procedure, thus having considerable advantages over the currently used approach, which is based upon the testing of a biopsy sample. The sensor has been implemented in 65[Formula: see text]nm CMOS technology and post-layout simulations confirm the theoretical claims we made and sensor exhibits sensitivity. Circuit consumes 45[Formula: see text]uW from 1.5[Formula: see text]V power supply. The circuit occupies 0.01954[Formula: see text]mm2 silicon area.

This paper describes a technique to detect blood cell levels based on the time-period modulation of a relaxation oscillator loaded with an Inter-Digitated Capacitor (IDC). A digital readout circuit has been proposed to measure the time-period difference between the two oscillators loaded with samples of healthy and (potentially) unhealthy blood. A prototype circuit was designed in 65-nm CMOS technology and post-layout simulations show 15.25-aF sensitivity. The total circuit occupies 2,184-[Formula: see text]m2 silicon area and consumes 216[Formula: see text][Formula: see text]A from a 1-V power supply.

This paper exploits the CMOS beta multiplier circuit to synthesize a temperature-independent voltage reference suitable for low voltage and ultra-low power biomedical applications. The technique presented here uses only MOS transistors to generate Proportional To Absolute Temperature (PTAT) and Complimentary To Absolute Temperature (CTAT) currents. A self-biasing technique has been used to minimize the temperature and power supply dependency. A prototype in 65[Formula: see text]nm CMOS has been developed and occupies 0.0039[Formula: see text]mm2, and at room temperature, it generates a 204[Formula: see text]mV reference voltage with 1.3[Formula: see text]mV drift over a wide temperature range (from [Formula: see text]40[Formula: see text]C to 125[Formula: see text]C). This has been designed to operate with a power supply voltage down to 0.6[Formula: see text]V and consumes 1.8[Formula: see text]uA current from the supply. The simulated temperature coefficient is 40[Formula: see text]ppm/[Formula: see text]C.

Immune thrombocytopenic purpura (ITP), due to the production of antiplatelet antibodies, is the most prevalent etiology of thrombocytopenia in children and a frequent cause of consultation for the pediatrician. We review here a series of Lebanese pediatric patients presenting with ITP and we discuss the relevant characteristics of the group. Study : A retrospective chart analysis was performed for 40 hospitalized or out-patient children presenting with ITP between January 1998 and December 2001. All cases except two had a diagnosis confirmed by bone marrow aspirate. Patients were equally distributed between the sexes with a mean age of 56 months. More than half of the patients had an episode of fever 2 days to 8 weeks prior to the diagnosis. For 42% of them, the disease appeared in the months between January and March. Ten percent presented with epistaxis but all of these had a platelet count less than 12,000. One-third of the patients had received immunization 2–8 weeks before the diagnosis, with one patient having a relapse 4 weeks after mumps–measles–rubella (MMR) immunization, which was 1 year after the initial cure. Initial treatment consisted of either steroids or intravenous polyvalent immunoglobulin in 58 and 36% of the cases, respectively. None of the patients had life-threatening hemorrhage. Only 10% of the patients developed chronic ITP (unremitting after 6 months). Conclusion : ITP is generally a benign disease in infancy and childhood. Certain characteristics of ITP in this series, such as the seasonal variation and the post-vaccine ITP, will need to be better defined in larger prospective studies. Optimal treatment will eventually be targeted towards a better delineation of the disease phenotype.